1. Field of the Invention
The present invention relates to a relay server that enables communication to be performed between terminals connected to different LANs (Local Area Networks).
2. Description of the Related Art
Conventionally, a communication technology called a virtual private network (Virtual Private Network, VPN) has been known (for example, see Japanese Patent Application Laid-Open No. 2002-217938). The VPN is used for, for example, performing communication via the internet between terminals that are connected to LANs of a plurality of branch offices (stations) each located in one of a plurality of regions. Use of the VPN enables another LAN located in a distant place to be used as if it is a directly-connected network.
However, this type of system is often rigid, and it is not easy to build an expandable and flexible system. For example, in the communication system disclosed in Japanese Patent Application Laid-Open No. 2002-217938 mentioned above, it is impossible to build a virtual network by using only select portions of apparatuses included in the system. Additionally, even when a virtual network is normally operated at an initial stage, there is a possibility that it subsequently becomes impossible to appropriately build the virtual network if, for example, a change in a configuration or setting of a network apparatus occurs.